Acoustic Measures of Dysphonia in Amyotrophic Lateral Sclerosis

Laryngeal Aerodynamics, Acoustics, and Hypernasality in Children With Cleft Palate

OBJECTIVE

The objective of this study was to examine the relationship between laryngeal aerodynamics, acoustics, and hypernasality in children with cleft palate with or without lip (CP ± L).

METHOD

This study used a prospectively performed cross-sectional design. Fifty-six children between the ages of 6 and 17 years with CP ± L participated (Mage= 11.7, SD = 3.4; male = 32, female = 24). Children were separated into four groups based on auditory-perceptual ratings of hypernasality made using the Cleft Audit Protocol for Speech-Augmented-Americleft Modification protocol. Laryngeal aerodynamic measures including subglottal pressure, transglottal airflow, laryngeal aerodynamic resistance (LAR), and phonation threshold pressure were collected. Acoustic measures of smoothed cepstral peak prominence (CPP) and low-to-high ratio on sustained vowels and connected speech were also considered. Analyses controlled for age, sex, auditory-perceptual ratings of voice quality, and speech intelligibility.

RESULTS

Children with minimally or mildly hypernasal resonance demonstrated significantly increased subglottal pressure, reduced transglottal airflow, and increased LAR, when compared with children with balanced or moderately hypernasal resonance. CPP on sustained vowel was significantly lower for children with moderate hypernasality when compared with all other groups-suggesting poorer voice quality. Other acoustic measures were in or near normative pediatric range.

CONCLUSIONS

Children with CP ± L and minimal or mildly hypernasal resonance demonstrated aerodynamic voice measures indicative of vocal hyperfunction. These findings suggest that children with CP ± L may compensate for velopharyngeal dysfunction on a laryngeal level, thus increasing the risk of laryngeal pathology. Future study should explore the relationship between laryngeal function and velopharyngeal port closure and consider how voice problems can be prevented or mitigated in children with CP ± L.

Artificial intelligence empowered voice generation for amyotrophic lateral sclerosis patients

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that can result in a progressive loss of speech due to bulbar dysfunction, which can have significant negative impact on the patient's mental well-being. Alternative Augmentative Communication (AAC) strategies based on synthetic voices have been shown to assist patients in maintaining communication and improving their Quality of Life (QoL). However, such synthetic voices are often perceived as impersonal and fail to capture the unique voice and identity of the patient. To tackle this issue, combining voice banking (VB) and artificial intelligence (AI) has emerged as a more natural communication strategy, enabling individuals to preserve their voice for use with AAC devices as needed. This involves recording speech samples to generate a synthetic voice closely resembling the individual's own. Despite the increasing interest in VB, there's a lack of clear strategies for its effective implementation in rapidly progressing diseases like ALS. Additionally, the perceptual quality of VB on patients with preserved speech, especially when offered early in the disease, remains poorly understood. In light of these challenges, this study aims to assess the effectiveness and the perceptual impact of AI-generated voices on ALS patients with preserved speech, utilizing a personalized voice synthesis system based on machine learning. The AI-generated patient-specific voice is achieved through voice recording, followed by fine-tuning using a Generative Adversarial Network for Efficient and High Fidelity Speech Synthesis (HiFi-GAN), resulting in a model capable of producing speech highly similar to the patient's own voice, with exceptional expressive and audio quality. By addressing these aspects, this study intends to offer valuable insights into the potential benefits and challenges of combining VB with AI voices to enhance communication support for ALS patients.

A multimodal approach to automated hierarchical assessment of bulbar involvement in amyotrophic lateral sclerosis

Introduction

As a hallmark feature of amyotrophic lateral sclerosis (ALS), bulbar involvement leads to progressive declines of speech and swallowing functions, significantly impacting social, emotional, and physical health, and quality of life. Standard clinical tools for bulbar assessment focus primarily on clinical symptoms and functional outcomes. However, ALS is known to have a long, clinically silent prodromal stage characterized by complex subclinical changes at various levels of the bulbar motor system. These changes accumulate over time and eventually culminate in clinical symptoms and functional declines. Detection of these subclinical changes is critical, both for mechanistic understanding of bulbar neuromuscular pathology and for optimal clinical management of bulbar dysfunction in ALS. To this end, we developed a novel multimodal measurement tool based on two clinically readily available, noninvasive instruments-facial surface electromyography (sEMG) and acoustic techniques-to hierarchically assess seven constructs of bulbar/speech motor control at the neuromuscular and acoustic levels. These constructs, including prosody, pause, functional connectivity, amplitude, rhythm, complexity, and regularity, are both mechanically and clinically relevant to bulbar involvement.

Methods

Using a custom-developed, fully automated data analytic algorithm, a variety of features were extracted from the sEMG and acoustic recordings of a speech task performed by 13 individuals with ALS and 10 neurologically healthy controls. These features were then factorized into 10 composite outcome measures using confirmatory factor analysis. Statistical and machine learning techniques were applied to these composite outcome measures to evaluate their reliability (internal consistency), validity (concurrent and construct), and efficacy for early detection and progress monitoring of bulbar involvement in ALS.

Results

The composite outcome measures were demonstrated to (1) be internally consistent and structurally valid in measuring the targeted constructs; (2) hold concurrent validity with the existing clinical and functional criteria for bulbar assessment; and (3) outperform the outcome measures obtained from each constituent modality in differentiating individuals with ALS from healthy controls. Moreover, the composite outcome measures combined demonstrated high efficacy for detecting subclinical changes in the targeted constructs, both during the prodromal stage and during the transition from prodromal to symptomatic stages.

Discussion

The findings provided compelling initial evidence for the utility of the multimodal measurement tool for improving early detection and progress monitoring of bulbar involvement in ALS, which have important implications in facilitating timely access to and delivery of optimal clinical care of bulbar dysfunction.

Comparison of Vowel and Sentence Intelligibility in People With Dysarthria Secondary to Amyotrophic Lateral Sclerosis

PURPOSE

In this study, we examined the utility of vowel intelligibility testing for assessing the impact of dysarthria on speech characteristics in people with amyotrophic lateral sclerosis (ALS). We tested the sensitivity and specificity of overall vowel identification, as well as that of vowel-specific identification, to dysarthria presence and severity. We additionally examined the relationship between vowel intelligibility and sentence intelligibility.

METHOD

Twenty-three people with ALS and 22 age- and sex-matched control speakers produced sentences from the Speech Intelligibility Test (SIT), as well as 10 American English monophthongs in /h/-vowel-/d/ words for the vowel intelligibility test (VIT). Data for SIT and VIT scores came from 135 listeners. Diagnostic accuracy of VIT measures was evaluated using the area under the curve of receiver operator characteristics. We then examined differences between control speakers, speakers with mild dysarthria, and speakers with severe dysarthria in their relationship between SIT and VIT scores.

RESULTS

The results suggest that the overall vowel intelligibility score showed high sensitivity and specificity in differentiating between speakers with and without dysarthria, even those with milder symptoms. In addition, single-vowel identification scores showed at least acceptable group differentiation between the mild and severe dysarthria groups, though fewer single vowels were acceptable discriminators between the control group and the group with mild dysarthria. Identification accuracy of /ɪ/ in particular showed excellent discrimination across all groups. Examination of the relationship between SIT and VIT scores suggests a severity-specific relationship. Speakers with SIT scores above 70% generally had higher SIT than VIT scores, whereas speakers with SIT below 70% generally had higher VIT than SIT scores.

DISCUSSION

Vowel intelligibility testing can detect speech impairments in speakers with mild dysarthria and residual articulatory function in speakers with severe dysarthria. Vowel intelligibility testing may, therefore, be a useful addition to intelligibility testing for individuals with dysarthria.

Acoustic Speech Analysis in Alzheimer's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The potential of biomarkers in the detection of Alzheimer's disease (AD) is prominent. Acoustics may be useful in this context but the evaluation and weighting for specific acoustic parameters on continuous speech is missing. This meta-analysis aimed to explore the significance of acoustic parameters from acoustic speech analysis on continuous speech, as a diagnostic tool for clinical AD.

METHODS

Applying PRISMA protocol, a comprehensive search was done in MEDLINE, Scopus, Web of Science, and CENTRAL, from 1960 to January 2024. Cross-sectional studies comparing the acoustic speech analysis between AD patients and healthy controls (HC), were taken into account. The bias risk of the included studies were examined via JBI checklist. Using Review Manager v.5.4.1, the mean differences of acoustic speech parameters among AD and HC were weighted, and the pooled analysis and the heterogeneity statistics were conducted.

RESULTS

In total, 1112 records (without duplicates) were obtained, and 11 papers with 7 acoustic parameters were included for this study, and 8 from 11 studies were identified with a low level of bias. Five from 7 acoustic parameters revealed significant differences among the two groups (p-values ≤ 0.01), in which for all rate-related and interruption-related acoustic parameters were the most prominent and less in temporal-related acoustic parameters.

CONCLUSIONS

Although a small number of acoustic parameters on continuous speech could be evaluated in the detection of clinical AD, the greatest potential of acoustic biomarkers for AD appeared to exist in two of three categories. Further contributions of high-quality studies are needed to support evidence for acoustics as biomarkers for AD.